Water tunnels are tunnels (below-ground channels) used to transport water to areas with large populations or agriculture. They are frequently part of

aqueducts Aqueduct may refer to: Structures *Aqueduct (bridge), a bridge to convey water over an obstacle, such as a ravine or valley *Navigable aqueduct, or water bridge, a structure to carry navigable waterway canals over other rivers, valleys, railw ...

. Some aqueducts, such as the

Delaware Aqueduct The Delaware Aqueduct is an aqueduct in the New York City water supply system. It takes water from the Rondout, Cannonsville, Neversink, and Pepacton reservoirs on the west bank of the Hudson River through the Chelsea Pump Station, then into ...

are single long tunnels. In other cases, such as the San Jacinto tunnel on the

Colorado River Aqueduct The Colorado River Aqueduct, or CRA, is a water conveyance in Southern California in the United States, operated by the Metropolitan Water District of Southern California (MWD). The aqueduct impounds water from the Colorado River at Lake Hav ...

, water tunnels form parts of far longer aqueducts. In cases where the outflow of a water tunnel is into an existing stream or river flowing to the point of water use, the term aqueduct is less likely to be used, as with the Harold D. Roberts Tunnel from

Dillon Reservoir Dillon Reservoir, sometimes referred to as Lake Dillon, is a large fresh water reservoir located in Summit County, Colorado, United States, south of I-70 and bordered by the towns of Frisco, Silverthorne, and Dillon. It is a reservoir for the ...

to the

North Fork South Platte River The North Fork South Platte River is a tributary of the South Platte River, approximately 50 miles (80 km) long, in central Colorado in the United States. The river is located near the headwaters of the South Platte in the Rocky Mountains so ...

Notable water tunnels, or systems including water tunnels

* Alva B. Adams Tunnel from the western slope of the

Colorado River The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid watershed that encompasses parts of seven U.S. s ...

drainage to the eastern

Front Range The Front Range is a mountain range of the Southern Rocky Mountains of North America located in the central portion of the U.S. State of Colorado, and southeastern portion of the U.S. State of Wyoming. It is the first mountain range encountered ...

of Colorado, *

Angeles Tunnel The Angeles Tunnel is a , water tunnel located in the Sierra Pelona Mountains in Los Angeles County, California, about north of Los Angeles."Angeles Tunnel", U.S. Geological Survey.''Pyramid Lake'' 2000, p. 1.American Society 1970, p. 131. It ...

7.2 mile (11.6 km) *

Bagur Navile Tunnel Bagur Navile Tunnel is the longest water tunnel in India. It was constructed between 1979 and 1990 and is located between the Bagur and Navile villages of Channarayapatna taluk of Hassan district, Karnataka. Length The tunnel is 9.7 kilometers ...

6 miles (9.7 km) * Bosporus Water Tunnel *Chicago

Tunnel and Reservoir Plan The Tunnel and Reservoir Plan (abbreviated TARP and more commonly known as the Deep Tunnel Project or the Chicago Deep Tunnel) is a large civil engineering project that aims to reduce flooding in the metropolitan Chicago area, and to reduce the harm ...

109.4 miles (176.1 km) *

Denver Water Denver Water serves 1.4 million people in the City and County of Denver, Colorado, and a portion of its surrounding suburbs. Established in 1918, the utility is a public agency funded by water rates and new tap fees, not taxes. It is Colorado's ...

Moffat Tunnel The Moffat Tunnel is a railroad and water tunnel that cuts through the Continental Divide in north-central Colorado. Named after Colorado railroad pioneer David Moffat, the tunnel's first official railroad traffic passed through in February 192 ...

6.2 miles (10.0 km) **Harold D. Roberts Tunnel from

23.3 miles (37.5 km) *Dingshan Tunnel on the

Irtysh–Karamay–Ürümqi Canal The Irtysh–Karamay–Ürümqi Canal (), also known as the Project 635 () Canal, is a system of water-transfer canals and reservoirs in the northern part of China's Xinjiang Uighur Autonomous Region. It transfers water from the Irtysh River (whi ...

(China) 4.6 miles 7.4 km *

Metropolitan Water District of Southern California The Metropolitan Water District of Southern California is a regional wholesaler and the largest supplier of treated water in the United States. The name is usually shortened to "Met," "Metropolitan," or "MWD." It is a cooperative of fourteen cit ...

** San Jacinto Tunnel on the

13 mi (21 km) *

New York City water supply system A combination of aqueducts, reservoirs, and tunnels supplies fresh water to New York City. With three major water systems ( Croton, Catskill, and Delaware) stretching up to away from the city, its water supply system is one of the most exte ...

Catskill Aqueduct The Catskill Aqueduct, part of the New York City water supply system, brings water from the Catskill Mountains to Yonkers where it connects to other parts of the system. History Construction commenced in 1907. The aqueduct proper was completed ...

28 miles (45 km) of grade tunnel, 35 miles (56 km) of pressure tunnel. **

85 miles (137 km) **

New York City Water Tunnel No. 3 New York City Water Tunnel No. 3 is a water-supply tunnel forming part of the New York City water supply system. It is being built by the New York City Department of Environmental Protection to provide New York City with a third connection to it ...

60 miles (97 km) *

Päijänne Water Tunnel The Päijänne Water Tunnel (, ) is a water tunnel located in Southern Finland. At , it is the second-longest tunnel in the world, running at a depth of in the bedrock. The purpose of the tunnel is to provide fresh water for the over one milli ...

75 miles (120 km) * San Juan-Chama Project ** Azotea Tunnel 12.8 miles (20.6 km) * The Inter-reservoirs Transfer Scheme (IRTS) in Kwai Chung and Sha Tin, New Territories, Hong Kong

Notable water tunnels, or systems including water tunnels

See also